There was an ominous hissing of air that sounded peculiar; but when she got her weight of water, she slowly settled on the mud bottom in twenty-three feet of water.
"Now get at your compressed air and see how she will go on the bottom," said Paul to the engineer as soon as they felt they were down.
She wheezed and groaned and moved slightly on the mud; but she refused to rise.

Groping about with his lantern, the engineer found something was the matter with the valves as lie could not get one of them to work and he grew excited.

He was advised to keep cool as there was no danger but they would get out all right.

For five or six minutes, which seemed an hour to the men thus caught in a trap, they tried every possible way to get the machinery to work; but it was useless.

The boat refused to rise.